org.quasiliteral.syntax
Class Indenter

java.lang.Object
  |
  +--org.quasiliteral.syntax.Indenter

public class Indenter

extends Object

Untamed: Keeps track of indentation info for BaseLexer's subclasses and clients.

Author:

Mark S. Miller, Terry Stanley

Field Summary

private char[]	myCloserStack The closers -- close bracketing characters that would close the currently unclosed open brackets
private int[]	myIndentStack The indentation level associated with each unclosed open bracket
private int	myNest How many block-levels deep am I?
private boolean[]	myNestStack Was this open bracket also a nesting?
private Twine[]	myOpennerStack The openners are Twine for reporting located errors at close time
private int	myTOS My top-of-stack is the same as the number of unclosed open bracketing characters.

Constructor Summary

Indenter()
Enabled:

Method Summary

int	getCloseIndent() Enabled: If the character that would close the most recently open bracket (getCloser()) were typed, where should it be indented?
char	getCloser() Enabled: Which character would close the most recent open bracket?
int	getIndent() Enabled: How indented should a vanilla new line be in this context?
private Object	grow(Object array)
void	nest(Twine openner, char closerChar) Enabled: Push a nester
void	pop(char closerChar, Twine closer) Enabled: Process a closing bracket by popping the stacks.
void	popIf(char closerChar) Enabled: If the tos is closerChar, then process a closing bracket by popping the stacks.
void	push(Twine openner, char closerChar, int indent) Enabled: Push a non-nester
private void	push(Twine openner, char closerChar, int indent, boolean isNest) Internal push
void	requireEmpty(String msg) Enabled:
String	toString() Suppressed: Show closing stack

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

myNest

private int myNest

How many block-levels deep am I?

Each open-bracketing character at the end of a line introduces a new nesting level. Each nesting level counts for four spaces.

myTOS

private int myTOS

My top-of-stack is the same as the number of unclosed open bracketing characters.

The stack keeps track of unclosed open brackets, and what indent should be assigned to new lines within that bracket (should it be the most recent -- the top of stack).

myOpennerStack

private Twine[] myOpennerStack

The openners are Twine for reporting located errors at close time

myCloserStack

private char[] myCloserStack

The closers -- close bracketing characters that would close the currently unclosed open brackets

We start the stack off with an indent level of zero and a dummy closer character.

myIndentStack

private int[] myIndentStack

The indentation level associated with each unclosed open bracket

myNestStack

private boolean[] myNestStack

Was this open bracket also a nesting?

I.e., was the openner the last character on its line? If so, then its popping should also decrement myNest.

Constructor Detail

Indenter

public Indenter()

Enabled:

Method Detail

grow

private Object grow(Object array)

push

private void push(Twine openner,
                  char closerChar,
                  int indent,
                  boolean isNest)

Internal push

nest

public void nest(Twine openner,
                 char closerChar)

Enabled: Push a nester

push

public void push(Twine openner,
                 char closerChar,
                 int indent)

Enabled: Push a non-nester

pop

public void pop(char closerChar,
                Twine closer)

Enabled: Process a closing bracket by popping the stacks.

If the opening was also a nesting, this decrements the nest level.

Parameters:

closerChar - As an error check, 'closerChar' must be the closing bracket character needed to close the most recent unclosed bracket.

closer - Used by some syntax errors to report where the erronous closing text occurs.

requireEmpty

public void requireEmpty(String msg)

Enabled:

popIf

public void popIf(char closerChar)

Enabled: If the tos is closerChar, then process a closing bracket by popping the stacks.

If the opening was also a nesting, this decrements the nest level.

Parameters:

closerChar - Checks whether 'closerChar' is the closing bracket character needed to close the most recent unclosed bracket.

getIndent

public int getIndent()

Enabled: How indented should a vanilla new line be in this context?

A vanilla new line is one that doesn't begin with a close bracketing character (for these, use pop()'s return value), and one that's not continuing a previous line by virtue of a binary operator or a backslash

getCloser

public char getCloser()

Enabled: Which character would close the most recent open bracket?

getCloseIndent

public int getCloseIndent()

Enabled: If the character that would close the most recently open bracket (getCloser()) were typed, where should it be indented?

toString

public String toString()

Suppressed: Show closing stack

Overrides:

toString in class Object

Returns:

a string representation of the object.